Hua Hin is about 200km (125 miles) from the capital Bangkok while the province of Phuket is in the far south.

Both places, as well as Phang Nga, are known for their scenic beaches. Two bombs went off in front of police stations in Surat Thani within the space of half an hour.

Wendy Herbert, an Australian expatriate who lives in Hua Hin, told the BBC the place was deserted on Friday.

"The main arterial road that runs through, that was near the bomb site, has just been shut down," she said.

"So basically what everyone has been told is stay at home, and I think it's unfortunate because it's Mother's Day and the Queen's birthday in Thailand, so it's a big kind of event day, where everybody would be out and doing things."

Image copyrightReutersImage caption
An injured person is rushed away from a bomb blast site in Hua Hin

Who could be behind the attacks?

Police said they had detained some suspects but ruled out international terrorism.

"Initial investigations reveal that two types of bombs were used, which are fire bombs and improvised explosive devices, or IEDs," said Royal Thai Police Col Krisana Patanacharoen.

The bombings, he was quoted as saying by the Associated Press news agency, followed a "similar pattern used in the southern parts of the country".

The BBC's Jonathan Head in Bangkok says that if southern rebels are behind these attacks, it would mark a significant change of tactics. The 12-year conflict in the south has killed more than 6,000 people, but has never targeted tourists.

Security has been tightened in the tourist areas and at airports in southern Thailand.

Foreign embassies have advised tourists to be vigilant. The UK Foreign Office has advised people in tourist areas to "exercise extreme caution, avoid public places and follow the advice of local authorities".

Thailand's southern insurgency

The country's Muslim minority largely originates in the three southernmost provinces of Yala, Pattani and Narathiwat

Insurgents have been fighting since the early 2000s for an independent Islamic state modelled on the old Malay sultanate of Pattani

Security forces, government workers and local Buddhist communities have been targeted in drive-by shootings, bombings and beheadings

The violence has been largely confined to the south

The Thai military and pro-government vigilantes have been accused of a heavy-handed response, including the torture and execution of prisoners